Retrieval device

ABSTRACT

An endoscopic surgical device for retrieving severed tissue or foreign bodies from within a subject is disclosed. The device comprises a support unit and a tissue retrieving net system. The net system is carried by the support unit and may be inserted into the subject through an orifice or small incision and operated to retrieve tissue that has been severed by a conventional method. The net system comprises a net, a net actuator, a net deployment and retrieval assembly for transmitting motion between the net and its actuator. The net system further comprises at least one net connector disposed such that only one connector is within an articulation zone, defined by locations of severe bending of the device during operation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims benefit of U.S. PatentProvisional Application Ser. No. 60/292,168, entitled “RetrievalDevice,” filed on May 18, 2001.

FIELD OF THE INVENTION

The present invention relates to surgical devices and more particularlyto endoscopic retrieval devices constructed for retrieving relativelysmall pieces of sample tissue or foreign bodies from a human subjectthrough orifices or small incisions.

BACKGROUND OF THE INVENTION

Snares, baskets, and graspers are in widespread use for severingcapturing and retrieving tissue specimens and foreign bodies from withinsubjects. The devices are used in human and animal subjects, inlaparoscopic surgeries and other procedures where access within asubject is only possible via a small opening. One exemplary use is forcutting off and retrieving intestinal polyps where a wire snare, passedthrough an colonoscope instrument channel, encircles and is tightenedabout an intestinal polyp to sever the polyp. The severed polyp isretrieved in a net inserted through the instrument channel. The net ismanipulated to enclose the polyp and then withdrawn with the instrumentso that the tissue architecture remains undisturbed.

In this procedure, as well as others, the net and snare must be quitecompact in order to pass into the subject through the instrumentchannel, or other passage. Prior art proposals have employed snaressupported within plastic tubes that were snaked into the subject tolocate the snare where desired. The snare was then deployed from itstube, manipulated to cut off the polyp and retrieved into the tube forremoval from the subject.

A net, collapsed within another tube, was introduced through theinstrument channel, etc., for removing the polyp. When near a targetpolyp, the net was deployed, like the snare, and manipulated to net thepolyp. The net was then closed sufficiently to secure the polyp andwithdrawn from the subject.

U.S. Pat. No. 5,643,283 to Younker, which is incorporated herein byreference in its entirety, discloses a device for retrieving an objectfrom within a subject. The device comprises a shaft and a compressiblepouch for receiving the object positioned adjacent a distal end of theshaft. The pouch includes a mouth which can be opened and closed. Thepouch is retained, in proximity to the distal end of the shaft, on acable loop by a slidable tether. The net is free to slide on the cableloop to form a pouch at the distal end of the shaft. The tether is fixedat a second location near the proximal end of the shaft, and in oneembodiment, is tied off to a ring and secured with heat shrink tubing.When the targeted foreign object is within the pouch, a cliniciandisengages the ring portion of the handle to close the net around theobject. The clinician then removes the device from the patient andunloads the object from the net. The clinician then places the ring on apost, in order to pack the pouch into the distal end of the shaft.

In operation of a commercial embodiment of U.S. Pat. No. 5,643,283,several problematic issues have surfaced. Clinicians have experienceddifficulty in understanding the operation of the tether, in particular,the interaction of the ring and post. The ring is to be used to pull thenet inside the shaft only when an object is not within the net. Inpreparation to capture an object, the ring should be disengaged torelease the net. The net is then slid over the targeted object and thenet is closed. At this point, proper operation would involve merelyremoving the device from the patient. However, some clinicians whenoperating the device try to further pull the net inside the shaft whenthe net is bundled up at distal end of cable loop. This will cause thenet to jam, or in some cases, damages the tubing. The occasionalimproper operation of the device sometimes causes permanent malfunction.

The commercial embodiment discussed above also adds undesirable expenseto the product. Specifically, the full length tether and heat shrinkoperation add material cost and labor assembly cost to the device.

The present invention provides a new and improved retrieval device thatis so constructed and arranged that net movement during deployment andretrieval is not prohibitively restricted. Secure net attachment isassured and that provides for convenient net packing in the introducerpassage. The device provides a convenient and economical method ofsample retrieval during endoscopic procedures. The new retrieval deviceis easy assemble, manufactured at a reduced cost, and easier to use bythe end consumer.

SUMMARY OF THE INVENTION

In one illustrated embodiment of the present invention an endoscopicsurgical device for retrieving severed tissue from within a humansubject is provided. The device includes a support unit and a tissueretrieving net system.

The support unit includes a body and an elongated introducer member. Thebody defines a first passage therethrough. The introducer has a firstend section proximal and fixed with respect to the body and a second endsection remote from the body. The introducer member further defines asecond passage aligned with the first passage and opening at the secondend section.

The tissue retrieving net system includes a net, a net deployment andretrieval assembly and a net actuator system.

The net includes a wire-like resilient loop and a net element having amouth section slidably disposed on the loop and a tissue receiving pouchsection. The loop terminates with two relatively parallel loop cables.The net is disposed adjacent the second end for deployment andretraction through the second passage opening.

The net deployment and retrieval assembly extends substantially throughthe first and second passages and connects to the net. The assemblyfurther includes a motion transmitting member extending in the secondpassage to the loop.

The net actuator unit includes a first handle fixed with respect to thebody and a second handle fixed with respect to the motion transmittingmember and movable relative to the first handle. The act of shifting thesecond handle relative to the first handle shifts the net into and outof the second passage opening.

The introducer member second passage has a diameter substantiallysmaller than the width of the loop as deployed. The member engages theloop at the second end section opening and resiliently collapses andelongates the loop as the net is retracted and moves into the introducermember passage. The loop resiliently returns to its uncollapsedconfiguration as it is deployed.

In one embodiment, the net system includes at least one connectoradapted to fasten each loop cable. The ends of the net element aresecured to the motion transmitting member on the proximal side of the atleast one connector with respect to the support unit.

In a second embodiment, the net system further includes a firstconnector, a second net connector proximal to the second passageopening, and an intermediate portion defined by an axial space on theloop cables between the first connector and the second connector. Thefirst connector and the second connector are adapted to fasten each loopcable. Ends of the net element are secured to the loop within theintermediate loop portion between the first connector and the secondconnector.

The deployment and retrieval assembly may include a thin, flexiblewire-like motion transmitting member between the net actuator unit andthe loop. The motion transmitting member extends within an introducerguide passage which closely surrounds the motion transmitting member andconstrains the member for translational longitudinal motion within thepassage.

The first connector may be disposed at least 6 inches from the secondconnector, such that only one connector is within an articulation zoneduring deployment of the net element.

The ends of the net element may be secured to the motion transmittingmember adjacent a proximal shoulder of the connector with respect to thesupport unit.

The present invention offers advantages over devices available in theprior art. In a second embodiment, the net is fixed distally andproximally by the use of a first and second connector. The connectorsare sufficiently spaced apart to provide secure net attachment withoutthe use of additional tether mechanisms. The connectors are positionedsuch that only one may be within an articulation zone of the endoscopeat a time, permitting ease of net deployment in a variety of geometricoperating configurations.

In a first embodiment, only one connector is used to secure the proximalside of the net. This technique decreases the amount of cable looplength within the articulation zone. The reduction in cable loop lengtheffectively reduces the amount of rigid material within the articulationzone of the endoscope at a time, further permitting ease of netdeployment in a variety of geometric operating configurations.

The device is also easier to assemble and less expensive to manufacturethan certain conventional designs.

Further features and advantages of the invention will become apparentfrom the following detailed description made with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a surgical device constructed accordingto one embodiment of the present invention, illustrated with the netelement deployed;

FIG. 2 is a view similar to FIG. 1, illustrated with the net elementretracted;

FIG. 3 is an enlarged fragmentary view of a part of the deviceillustrated in FIG. 1, showing detail of the introducer member;

FIG. 4 is a enlarged fragmentary view of part of the device illustratedin FIG. 1, with the device show as positioned in a sample configurationwithin a subject;

FIG. 5 is an enlarged fragmentary view of part of a surgical deviceconstructed according to a second embodiment of the present invention,showing detail of the introducer member, and

FIG. 6 is a enlarged fragmentary view of part of the device illustratedin FIG. 5, with the device show as positioned in a sample configurationwithin a subject.

BEST MODE CONTEMPLATED FOR CARRYING OUT THE INVENTION

An endoscopic surgical device 10 for retrieving severed tissue and orforeign bodies from within a subject is illustrated by the drawings.Referring to FIGS. 1 and 2, in one embodiment, the device 10 comprises asupport unit 12 and a tissue retrieving net system 16. The net system iscarried by the unit 12 and is so constructed and arranged that it may beinserted into the subject through an orifice or small incision andoperated to retrieve a tissue sample previously detached from thesubject by a conventional method, e.g., a snare/cautery system.Accordingly, the net system 16 comprises a net 20, a net actuator 24,and a net deployment and retrieval assembly. 28 for transmitting motionbetween the net and its actuator 24. The net 20 comprises a net element21 and a net loop 22 and a distal 25 and proximal 26 tie off suture thatsecures the net.

The device 10 can be used with any suitable or conventional endoscopicor laparascopic surgical equipment. For purposes of this disclosure thedevice 10 is described in the context of use with anendoscope/colonoscope/sigmoidoscope type apparatus (not illustrated), ofconventional or suitable construction. The scope is provided with anelongated body having a controllably flexible projecting end region.Surgical instruments, such as the device 10, may be introduced throughan instrument channel, which extends through the scope body, forretrieving tissue targeted by the surgeon manipulating the scope.

The support unit 12 supports the net system 16 so that the net 20 can beinserted through the scope instrument channel by a surgeon. The supportunit 12 comprises a body 30 defining a passage and an elongatedintroducer 40 having a first end section 42 proximal and fixed withrespect to the body 20 and a second end section 44 remote from the body.The introducer 40 is tubular and aligned with the body passage forreceiving the net system.

The illustrated introducer 40 is a smooth, supple member capable ofbeing snaked through the scope instrument channel into the subject andreadily flexed into any shape required as the scope body is flexed bythe surgeon. In the illustrated embodiment, the introducer 40 is agenerally cylindrical, small diameter tube formed of non-reactive lowfriction plastic material, such as polytetrafluouroethylene. The firstend section 42 is fixed to the body 30 while the second end section 44houses the net for individual deployment and retrieval.

The net actuator 24 is adapted for reciprocating the deployment andretrieval assembly in the body and introducer to operate the net 20. Theactuator 24 comprises a first handle 50 fixed with respect to the body30 and a second handle 52 attached to the deployment and retrievalassembly 28 and movable with respect to the handle 50.

The second handle 52 is fixed to the assembly 28 and mounted on thehandle 50 between its ends for longitudinal sliding movement. The secondhandle comprises a dual finger ring member 80 slidable on the handle 50.The handles 50, 52 as illustrated are formed from molded plasticmaterials.

The deployment and retrieval assembly 28 is constructed and arranged totransmit considerable deployment and retractive forces to the net whileenabling the scope body to be freely manipulated and flexed to positionthe net where desired. The assembly 28 comprises a link comprises afirst link section 70 and a second link section 71 connected to theactuator 24 for transmitting compressive and tensile forces between thehandle 52 and a bore 58. The bore 58 is disposed within the center ofthe body 30. The link 70 transmits relatively substantial compressiveforces without bending or breaking. The illustrated first link section70 is formed from hypodermic needle stock, i.e., it is a cylindricalstainless steel tube. The second link section 71 as illustrated is amulti-strand cable. The first link section 70 joins the second linksection 71 as the link exits the body 30.

The link 71 extends from the body 30 and within the introducer 40 sothat it must flex with the introducer yet transmit compressive andtensile forces. The illustrated link 71 is closely surrounded by thebody passage of the introducer passage 40. The link 71 is relativelystiff compared to the supple introducer. When transmitting compressiveforces, the link 71 is resiliently deformed to bow against theintroducer wall. The link 71 has good compressive and tensile strengthand is somewhat resiliently bendable. The link 71 will bend appreciablywithout yielding and kinking.

A first connector 80 and a second connector 82 fix the loop 22 in twolocations with respect to the net 20. The proximal side of the net istied off at a location 85 between the loop cables. As illustrated inFIG. 3, a tether 27 is used to tie off the proximal side of the net.This tether is shorter than conventional tethers that travel the fulllength of the introducer. No further tethering system is required,although additional net mounting techniques may be employed in thepractice of the invention.

Referring now to FIG. 3, the first connector 80 joins the link 71 andthe loop 22 together structurally. The illustrated connector 80 is ashort tube crimped to both ends of the loop 22 and to the second linksection 71, The illustrated connector tube is crimped about the loop andlink to form a cross sectional shape, which is capable of rotatingwithin the introducer 40. The illustrated connector 80 is formed fromhypodermic needle stock, like the first link section 70. The secondconnector 82 further joins opposing portions on the net loop 22 at alocation proximal to the net 20 with respect to the first connector 80.

In the illustrated embodiment, the space between the two loop cables isutilized to fix the net element 21 with respect to the link 71. Anintermediate region R, shown in FIG. 3, axially between the firstconnector 80 and the second connector 82 within the introducer 40 may beused. In an exemplary embodiment, the proximal side of the net element21 with respect to the support system 12 is fixed to the net loops 22 ata convenient location 85. Suture material, or another known suitablemethod, may be used to tie the net to the loop.

The net 20 is deployed from the introducer second end 44 and manipulatedby the surgeon to net severed tissue and secure the tissue for retrievalfrom the subject. The net 20 may be deployed after a snare or similartechnique has severed the target tissue. The net 20 comprises apouch-like net element 21 slidably supported on the loop 22.

The illustrated net loop 22 is formed from a loop of fine wireconstructed and arranged to cooperate with the introducer to deploy andretract the net 20. The illustrated loop 22 is a stiff, resilientflexible wire having its respective ends crimped in place in twolocations by the first and second connector 80, 82. When the net isdeployed from the end of the introducer, the loop resiliently expands toa relaxed condition where the loop width is substantially greater thanthe introducer diameter. The deployed snare is guided to a positionwhere it receives a target polyp or other tissue. The net is retractedby the surgeon. As the net is retracted into the introducer second end44 the loop resiliently bears against the introducer wall so the loopresiliently collapses, narrowing the loop portion projecting from theintroducer. Tissue or another object captured within the net element 21is progressively constricted by the elastic nature of the net, allowingfor a wide range of sized objects to fit inside the net withoutcompromising the architecture preservation or the security of theobject, as the net is being drawn toward the distal end of theintroducer.

The net element 21 is an extremely light pouch-like structure having thenet loop wire extending through the mesh about its periphery to form anet mouth slidably supported on the loop and a depending pouch. The netfibers are quite fine, yet sufficiently strong that the net element mayslide along the loop wire in the direction away from the connectors 80,82 to enclose tissue within the pouch as the net is retrieved and/or togather the entire net at the distal net loop end when the net loop hasbeen retrieved. The net has minimal bulk so that when an empty net isretrieved, it easily moves completely into the introducer passage.

The illustrated net is formed from 100% nylon fibers having stranddiameters of from about 0.0125 mm-0.04 mm. The fibers are woven in adiamond mesh pattern with the mesh strands spaced from 1 mm-3 mm andtheir intersections fixedly secured together. The illustrated nettingmaterial is substantially like that of a fine mesh hair net. The net isformed by cutting about a square, circular or elliptical section of thenet, trimming or otherwise finishing the edges and threading the loopwire through the peripheral mesh elements. The cut net section size isselected sufficiently larger than the net loop area to assure that apouch-like, tissue receiving portion suspends from the net mouth, butnot too large to create undesirable bulk and difficulty packing the netwhen pulling it inside the shaft.

Attempting to fully retrieve a tissue containing net into the introducer40 can result in tissue loss by forcing the tissue through the net. Thenet fibers are fine and strong so they may cut the tissue or they may bebroken, either of which alternative is undesirable. A net actuator thumbring may be provided with a tag (not illustrated) warning the surgeonnot to continue retrieving the net against unusual resistance.

The present invention resolves problems faced by surgeons and nursesworking with some prior art designs. Nurses and doctors have experienceddifficulty in understanding the operation of the tether, specificallythe interaction of the ring and post. Therefore, occasionally the deviceis operated incorrectly causing malfunction. The present design allows anurse to pull back on the handle to conveniently pack the net inside theintroducer passage.

Further, often a surgeon is required to manipulate the endoscope intodifficult to access internal areas. Certain procedures require bendingor twisting the endoscope. The area of the endoscope that is twisted orbent is called the articulation zone.

Some net devices have featured multiple connector designs in which theconnectors are spaced somewhat adjacently with the second end section44. In these designs, the multiple connectors on the net devices haveresisted bending of the scope. Moreover, the friction created has madedeployment of the net difficult once the scope has been desirablypositioned by the surgeon. One advantage of the present invention isincreased freedom of movement, and ease of net deployment, within thearticulation zone.

During operation of the system 10, the surgeon experiences an increasedease of use over prior art designs. In the illustrated embodiment, thefirst connector 80 is axially disposed a distance from the secondconnector 82, such that only one connector is within the articulationzone (bounded by A₁,A₂), defined along the introducer 40 longitudinalaxis, during deployment of the net element. In the illustrated system,the first connector 80 is disposed at least six inches from the secondconnector 82.

The articulation zone defines the axial portion of the introducer 40within a substantially non-linear position. The articulation zonetypically includes bends of greater than 30° and can exceed 200° at aradius of 0.75 inches or less.

Referring to FIG. 4, a portion of the system 10 is illustrated aspositioned in a probable configuration within a subject. Duringoperation of the scope, a surgeon may manipulate the second end section44 of the introducer into a severe articulated position. At times, thesecond end section may be bent up to 180°, as illustrated in FIG. 4.Deployment of the net 20 in this and similar positions is difficult whenthe connectors 80, 82 are both within the articulation zone. Thecombined kinetic frictional force of each connector against the insideof the introducer passage would otherwise make deployment of the netdifficult. As illustrated in FIG. 4, the surgeon more easily deploys thenet in a variety of positions.

A second embodiment of the present invention is illustrated by thedrawings. A part of an endoscopic surgical device 10 for retrievingsevered tissue and or foreign bodies from within a subject isillustrated in FIGS. 5 and 6. In this illustrated design, the device 10includes a support unit 12 and net actuator 24 as previously described.However, an alternative construction of a net deployment and retrievalassembly 28 is utilized.

In the illustrated design, the net deployment and retrieval assembly 28uses a single connector. Referring now to FIG. 5, the connector 182joins the link 71 and the loop 22 together structurally. The illustratedconnector 182 is a short tube crimped to both ends of the loop 22 and tothe second link section 71. The illustrated connector tube is crimpedabout the loop and link to form a cross sectional shape, which iscapable of rotating within the introducer 40. The illustrated connector182 is formed from hypodermic needle stock, like the first link section70.

One goal of the design is to reduce the amount of rigid material withinthe articulation zone. During operation of the system 10, the surgeonexperiences an increased ease of use over prior art designs. Asillustrated in FIG. 6, the length of rigid material within thearticulation zone (bounded by A₁,A₂), defined along the introducer 40longitudinal axis, is minimized during operation of the net element. Thereduction in rigid material results from reducing the length of loopcable 22 within the articulation zone.

As shown in FIG. 5, the proximal side of the net element 21 with respectto the support system 12 is fixed to the net loops 22 at a convenientlocation 185. Suture material, or another known suitable method, may beused to tie the net to the loop. As illustrated in FIG. 5, a tether 27is used to tie off the proximal side of the net. This tether is shorterthan conventional tethers that travel the full length of the introducer.The tether 27 may be tied off adjacent the shoulder of the connector182. As shown, the tether has a diameter not greater than the thicknessof the connector shoulder. No further tethering system is required,although additional net mounting techniques may be employed in thepractice of the invention.

While two embodiments of the invention has been illustrated anddescribed in considerable detail, the present invention is not to beconsidered limited to the precise constructions disclosed. Variousadaptations, modifications and uses of the invention may occur to thoseskilled in the arts to which the invention relates. It is the intentionto cover all such adaptations, modifications and uses falling within thescope or spirit of the annexed claims.

What is claimed is:
 1. An endoscopic surgical device for retrievingsevered tissue or foreign bodies from within a human body, the devicecomprising: a. a support unit comprising: i. a body having a firstpassage therethrough, and ii. an elongated introducer member having afirst end section proximal and fixed with respect to said body and asecond end section remote from the body, the introducer member having asecond passage aligned with the first passage and opening at said secondend section; and b. a tissue retrieving net system comprising: i. a netcomprising a wire-like resilient loop and a net element having a mouthsection slidably disposed on the loop and a tissue receiving pouchsection, said loop terminating with two relatively parallel loop cables,said net disposed adjacent said second end section for deployment andretraction through said opening; ii. a net deployment and retrievalassembly extending substantially through said first and second passagesand connected to the net, said assembly comprising a motion transmittingmember extending in said second passage to said loop; and iii. a netactuator unit comprising a first handle fixed with respect to said bodyand a second handle fixed with respect to said motion transmittingmember and movable relative to said first handle so that shifting thesecond handle relative to said first handle shifts said net into and outof said opening; c. said second passage having a diametrical extentsubstantially smaller than the width of said loop as deployed, saidintroducer member engaging said loop at said opening and resilientlycollapsing and elongating said loop as said net is retracted and movesinto said second passage, said loop resiliently returning to itsuncollapsed configuration as it is deployed; d. said net system furthercomprising a connector, wherein the connector secures each loop cable;e. wherein with respect to said support unit, a proximal portion of saidnet element is secured to the motion transmitting member on the proximalside of the connector, and a distal portion of said net element issecured to a center portion of said loop.
 2. The device claimed in claim1 wherein said deployment and retrieval assembly comprises a thin,flexible wire-like motion transmitting member between the net actuatorunit and the loop, said motion transmitting member extending within anintroducer guide passage, said introducer guide passage closelysurrounding said motion transmitting member and constraining said memberfor translational longitudinal motion within said passage.